To check ignition coil power supply, disconnect primary wires at ignition coil. Turn ignition on. Using voltmeter, check voltage between coil positive terminal and ground of each ignition coil. Battery voltage should exist. If not, check battery feed. See Fig 1 .
To check power unit resistance, turn ignition off. Remove power unit from ignition coil. Align (2) 1.5-volt batteries in series to create a 3-volt power source. Using leads from the 3-volt power source, apply negative side to the "G" terminal and positive side to "IB" terminal.
Using an ohmmeter, connect the positive lead to terminal "G" and the negative lead to terminal "OC" of the power unit. See Fig 2 . Check continuity with 3-volt power source applied and again with power source removed. See SWIFT POWER UNIT TEST table. Replace power unit if test results are not within specification.

SWIFT POWER UNIT TEST

Application	Ohms
Voltage At Terminal "IB"	Continuity
No Voltage At Terminal "IB"	No Continuity

Fig 1: Ignition Coil Power Supply Test

Courtesy of SUZUKI OF AMERICA CORP.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Ignition Coil Power Unit